The invention pertains to a cutting tool assembly that uses a clamp assembly to secure the cutting insert to the holder. More specifically, the invention pertains to such a cutting tool assembly, and especially the clamp assembly, wherein the clamp assembly comprises a clamp and a coolant plate that facilitates enhanced delivery of coolant adjacent the interface between the cutting insert and the workpiece (i.e., the insert-chip interface) to diminish excessive heat at the insert-chip interface in the chipforming removal of material from a workpiece.
Metal cutting tools for performing metal working operations generally comprise a cutting insert having a surface terminating at a cutting edge and a tool holder formed with a seat adapted to receive the insert. The cutting insert engages a workpiece to remove material, and in the process forms chips of the material. Excessive heat at the insert-chip interface can negatively impact upon (i.e., reduce or shorten) the useful tool life of the cutting insert.
For example, a chip generated from the workpiece can sometimes stick (e.g., through welding) to the surface of the cutting insert. The build up of chip material on the cutting insert in this fashion is an undesirable occurrence that can negatively impact upon the performance of the cutting insert, and hence, the overall material removal operation. A flow of coolant to the insert-chip interface will reduce the potential for such welding. It would therefore be desirable to reduce excessive heat at the insert-chip interface to eliminate or reduce build up of chip material.
As another example, in a chipforming material removal operation, there can occur instances in which the chips do not exit the region of the insert-chip interface when the chip sticks to the cutting insert. When a chip does not exit the region of the insert-chip interface, there is the potential that a chip can be re-cut. It is undesirable for the turning insert to re-cut a chip already removed from the workpiece. A flow of coolant to the insert-chip interface will facilitate the evacuation of chips from the insert-chip interface thereby minimizing the potential that a chip will be re-cut.
There is an appreciation that a shorter useful tool life increases operating costs and decreases overall production efficiency. Excessive heat at the insert-chip interface contribute to the welding of chip material and re-cutting of chips, both of which are detrimental to production efficiency. There are readily apparent advantages connected with decreasing the heat at the insert-chip interface wherein one way to decrease the temperature is to supply coolant to the insert-chip interface.
It is undesirable for the chip to become long. Breaking of the chip into smaller pieces is a desirable event during the material removal operation. The coolant stream can impinge the chip to thereby break the chip into the smaller pieces.
Heretofore, systems operate to lower the cutting insert temperature during cutting. For example, some systems use external nozzles to direct coolant at the cutting edge of the insert. The coolant serves not only to lower the temperature of the insert but also to remove the chip from the cutting area. The nozzles are often a distance of one to twelve inches away from the cutting edge. This is too far of a distance for effective cooling. The farther the coolant must travel, the more the coolant will mix with air and the less likely it will be to contact the tool-chip interface.
There are cutting assemblies that utilize a clamping assembly that includes a clamp and a coolant plate. For example, in U.S. Pat. No. 7,883,299 to Prichard et al. for a Metal Cutting System for Effective Coolant Delivery [K-2379USUS1] there is shown a metal cutting system that includes a shim and a cutting insert, as well as a clamp that engages a plate on top of the cutting insert. Coolant flows toward the interface between the cutting insert and the workpiece.
As another example, in United States Patent Application Publication No. US2011/0020073 A1 for Cutting Insert Assembly and Components Thereof by Chen et al. [K-3049USUS 1/U.S. Ser. No. 12/874,591 ] there is shown a metal cutting assembly that includes a holder that receives a shim and a cutting insert. The assembly also includes a clamp and a coolant plate. Coolant flows toward the interface of the cutting insert and the workpiece.
Further, referring to [K-4080USUS1] Co-pending U.S. patent application Ser. No. 13/664,568 for Cutting Insert Assembly and Components Thereof by Henry et al., there is another cutting assembly that utilizes a clamping assembly that includes a clamp and a coolant plate, a pair of arms or prongs extended from the clamp to contact opposite side surfaces of the coolant plate and thereby secure the coolant plate in position. Such an arrangement requires that the clamp and the coolant plate be in a parallel relationship, i.e., the central longitudinal axis of the clamp and the central longitudinal axis of the coolant plate are parallel to one another. There should be an appreciation that an arrangement in which the clamp and coolant plate are parallel exhibits certain limitations in the context of trying to accommodate cutting inserts of various sizes and various holders in which the cutting insert has an orientation at different angles.
One such limitation is that different sizes of clamps and/or coolant plates are necessary to accommodate variations in the cutting inserts and the orientations of the cutting insert in the holder. This necessitates that a number of different clamps and coolant plates had to be kept in inventory to accommodate the variety of different cutting inserts. It would therefore be highly desirable to provide a clamping assembly of a clamp and coolant plate that exhibits a geometry so as to accommodate a number of different clamps and coolant plates without having to keep in inventory a variety of different cutting inserts. A reduction in the number of different clamps and/or coolant plates in inventory would result in a cost savings thereby increasing the overall efficiency of the cutting operation.